Which nerve exits the infraorbital canal via the infraorbital foramen?

• A. Infraorbital nerve
• B. PSA nerve
• C. MSA
• D. ASA

Answer: (A)

The key idea here is the exit route of the facial-sensory nerve that supplies the midface and anterior maxillary teeth. The infraorbital nerve is the continuation of the maxillary division of the trigeminal nerve (V2). It travels through the infraorbital canal and then exits the skull at the infraorbital foramen. Once it emerges, it gives off its dental branches to the maxillary front teeth and premolars (the anterior and middle superior alveolar portions) and provides sensory innervation to the lower eyelid, side of the nose, and cheek.

The other nerves have different pathways: the posterior superior alveolar nerve targets the molars and enters via posterior routes behind the maxillary sinus, while the anterior and middle superior alveolar branches are dental branches that come off the infraorbital nerve but do not themselves exit through the infraorbital foramen as separate exits. So, the infraorbital nerve is the one that exits the infraorbital canal specifically through the infraorbital foramen.